{"id": "1207027085350600707", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-03T09:00:00Z", "msg": "792\nWTPZ41 KNHC 030857\nTCDEP1\n \nHurricane Karina Discussion Number  28\nNWS National Hurricane Center Miami FL       EP112026\n1100 PM HST Wed Sep 02 2026\n\nWhile Karina continues to exhibit an annular appearance with a \nlarge ring of deep convection, its cloud-top temperatures have been \ngradually warming.  The eye of the hurricane has also expanded to a \ndiameter of 30 to 40 n mi.  Subjective Dvorak classifications from \nTAFB give a current intensity estimate of 102 kt and objective \nintensity estimates from UW-CIMSS range from 95 to 109 kt.  The \nadvisory intensity is set at 105 kt, near the higher end of the \nestimates.  A couple of recent scatterometer overpasses more or \nless confirmed the previously estimated 34- and 50-kt wind radii \nfor the hurricane.\n\nKarina continues with a west-northwestward motion at around \n285/10 kt.  The system should maintain this motion for the next 48 \nhours or so, under the influence of a subtropical ridge to its \nnorth.   Thereafter, a mid-tropospheric cyclone to the north \nof the Hawaiian Islands is expected to cause a slight northwestward \nbend in the track.  The official forecast is very similar to the \nprevious NHC track.  This is fairly close to the latest Google \nDeepMind and HFIP Corrected consensus predictions, which have \nproved to be quite reliable track guidance so far.\n\nVertical wind shear is forecast to remain low for the next 48 hours \nor so, with significantly increasing southwesterly shear likely \nlater in the forecast period.  Karina should move over gradually \ncooling ocean waters for the next several days, with the low- to \nmid-level air mass becoming increasingly dry.  Given these \nexpected environmental conditions, Karina should weaken during the \nforecast period, and become a post-tropical cyclone in 5 days or \nsooner.  The official intensity forecast is a little above the \nmodel consensus for the next 48 hours in consideration of the \nannular structure, but is close to the overall model guidance mean\nthereafter.\n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  03/0900Z 19.6N 135.7W  105 KT 120 MPH\n 12H  03/1800Z 20.0N 137.1W  100 KT 115 MPH\n 24H  04/0600Z 20.4N 138.9W   90 KT 105 MPH\n 36H  04/1800Z 20.9N 140.5W   80 KT  90 MPH\n 48H  05/0600Z 21.4N 142.0W   70 KT  80 MPH\n 60H  05/1800Z 22.1N 143.0W   60 KT  70 MPH\n 72H  06/0600Z 23.0N 144.1W   55 KT  65 MPH\n 96H  07/0600Z 24.6N 147.0W   45 KT  50 MPH\n120H  08/0600Z 26.3N 150.8W   30 KT  35 MPH...POST-TROPICAL\n \n"}